Modulation of Neuronal Ion Channels by 2nd Messengers

第二信使对神经元离子通道的调节

• 批准号: 7666411
• 负责人: MARK S SHAPIRO
• 金额: $ 1.9万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7666411
• 关键词: 1-Phosphatidylinositol 4-Kinase; Affinity; Arachidonic Acids; Behavior; Binding; Biochemical; Biochemistry; Biosensor; Biotinylation; Brain; Calmodulin; Cells; Chimera organism; Chromosome Pairing; Complementary DNA; Complex; Consciousness Disorders; Couples; Dependence; Development; Disease; Electricity; Electrophysiology (science); Elements; Emotional; Emotions; Epilepsy; Face; Family; Fluorescence; Fluorescence Resonance Energy Transfer; Funding; GTP-Binding Proteins; Ganglia; Goals; Health; Human; Hydrolysis; Imaging Techniques; Individual; Intervention; Ion Channel; Life; Mammalian Cell; Measurement; Measures; Mediating; Medical; Membrane; Memory; Methods; Molecular; Molecular Biology; Molecular Mechanisms of Action; Monitor; Moods; Motion; Muscle; Myxoid cyst; Nerve; Nervous system structure; Neurons; Organ; Organism; Pathway interactions; Phosphatidylinositol 4,5-Diphosphate; Phosphatidylinositols; Phospholipase C; Phosphoric Monoester Hydrolases; Phosphotransferases; Play; Point Mutation; Potassium Channel; Preparation; Probability; Proteins; Range; Receptor Signaling; Regulation; Regulatory Element; Research; Research Personnel; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Site; Specificity; Spectrum Analysis; Synapses; Syndrome; System; Testing; Therapeutic Intervention; Thinking; Work; analog; base; neuronal excitability; neurotransmitter release; novel; optical imaging; patch clamp; phosphatidylinositol phosphate; programs; protein activation; receptor; receptor coupling; reconstitution; research study; success; tissue/cell culture; tool; trafficking; voltage

DESCRIPTION (provided by applicant): Ion channel currents are the fundamental units of electrical activity in most organisms. In our nervous system, K+ and Ca2+ channels are critical, and their regulation provides a way to directly control neuronal excitability and release of neurotransmitter at synapses. The modulations are crucial to basic nervous function and their understanding should contribute to novel modes of medical interventions for a range of disorders involving the brain, nerves and muscles. We focus primarily on the family of Kv7 (KCNQ/M-type) K+ channels that underlies several neuronal K+ currents and on Cav2.2 (N-type) Ca2+ channels. In particular, we seek to elucidate the molecular mechanisms of several modulatory pathways that act on these types of ion channels. We use both a heterologous system in which cDNA clones of the channels, receptors and signaling molecules are expressed in mammalian tissue-culture cells, and a preparation of primary sympathetic neurons. Two pathways that we study have in common receptors coupled to the Gq/11 family of G proteins, the activation of phospholipase C, and hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2). Both Kv7 and Cav2.2 channels have emerged as being regulated by PIP2, and in this project we will investigate how PIP2 interacts with the channels, the site(s) of the interaction, and the parts of the channel proteins that mediate the regulation of gating. Stimulation of certain raises intracellular Ca2+ and acts on Kv7 channels in concert with calmodulin (CaM). We will further investigate the molecular mechanism by which Ca2+/CaM acts. Other Gq/11-coupled receptors do not raise intracellular Ca2+ and act by depleting the membrane of PIP2. Using a variety of approaches, we will probe this specificity in receptor action. The tools to be used include patch-clamp electrophysiology, molecular biology, biochemistry, and advanced imaging techniques. The molecules and signaling pathways that we study have broad relevance to human health and disease. Kv7 channels play a dominant role in regulating excitability of neurons, and their regulation likely underlies changes in emotional state, memory and regulation of body organs. Dysfunctional Kv7 channels cause specific epileptic syndromes. The modulation of Cav2.2 channels regulates release of neurotransmitter which is the basic signal at synapses between neurons. Thus, our research should provide the basis for the development of novel modes of therapeutic intervention for a variety of nervous diseases. Lay summary: This project studies how ion channels, which mediate the electricity in nerve cells, are regulated. We investigate these signals at the level of the molecule and the individual living cell using biophysical and molecular tools. We seek to understand this regulation of the nervous system that underlies the complex phenomena of human thought, emotion and behavior. Our findings may help to alleviate the many diseases of mood, motion and consciousness that are disorders of nervous function.

描述（由申请人提供）：离子通道电流是大多数生物体电活动的基本单位。在我们的神经系统中，K+和Ca2+通道至关重要，它们的调节提供了一种直接控制突触处神经递质的神经元兴奋性和释放的方法。该调制对于基本神经功能至关重要，它们的理解应为涉及大脑，神经和肌肉的一系列疾病的新型医疗干预方式做出贡献。我们主要关注KV7（KCNQ/M型）K+通道的家族，该家族构成了几个神经元K+电流和CAV2.2（N型）Ca2+通道的基础。特别是，我们试图阐明对这些类型的离子通道作用的几种调节途径的分子机制。我们使用的是一个异源系统，其中在哺乳动物组织培养细胞中表达了通道，受体和信号分子的cDNA克隆，并制备原发性交感神经元。我们研究的两种途径具有与G蛋白的GQ/11家族耦合的常见受体，磷脂酶C的激活以及磷脂酰肌醇4,5-双磷酸盐的水解（PIP2）。 KV7和CAV2.2通道都已由PIP2调节，在此项目中，我们将研究PIP2如何与通道，相互作用的位点以及介导检测调节的通道蛋白的部分相互作用。刺激某些会增加细胞内Ca2+，并与钙调蛋白（CAM）一起在KV7通道上作用。我们将进一步研究Ca2+/CAM起作用的分子机制。其他GQ/11耦合受体不会通过耗尽PIP2的膜来引起细胞内Ca2+。使用多种方法，我们将在受体作用中探测这种特异性。要使用的工具包括贴片钳电生理学，分子生物学，生物化学和高级成像技术。我们研究的分子和信号通路与人类健康和疾病具有广泛的相关性。 KV7通道在调节神经元的兴奋性方面起主要作用，其调节可能是情绪状态，记忆和身体器官调节的变化的基础。功能失调的KV7通道引起特定的癫痫综合征。 CAV2.2通道的调节调节神经递质的释放，这是神经元之间突触的基本信号。因此，我们的研究应为各种神经疾病的新型治疗干预方式开发的基础。摘要摘要：该项目研究了如何调节神经细胞中电力的离子通道。我们使用生物物理和分子工具在分子和单个活细胞水平上研究这些信号。我们试图理解这种神经系统的调节，这是人类思想，情感和行为的复杂现象的基础。我们的发现可能有助于缓解许多情绪，运动和意识的疾病，这些疾病是神经功能的疾病。